Large machines, such as those used in earth moving applications, frequently include a hub having both a brake drum and a clutch drum that are used to operate the machine. Typical of such a machine is a Lima 2400 dragline having a brake and clutch hub. Both the brake and the clutch may function by clamping and releasing frictional bands against the respective drums. In so doing a large amount of heat is generated and must be dissipated in some fashion or the drum will become damaged, e.g. by heat stress cracking. In the prior art these drums have been designed as two concentric rings separated from each other by, and rigidly connected to each other by spaced radial webs inclined at an angle to the axis of rotation. It was anticipated that the webs would serve as fan blades to cause great volumes of air to pass through between the drums and keep them cool enough to avoid damage by heat stress cracking. This hope has not materialized, and such hubs have been found to have a relatively short life due to heat stress cracking.
It is an object of this invention to provide an improved brake and clutch hub for earth moving machinery. It is another object of this invention to provide a brake and clutch hub which will operate without fear of damaging heat stresses. Still other objects will appear from the more detailed description which follows.